Effects of Velocity on Elastic Deformation in Ball Screw Drives and its Compensation

2017 ◽  
Author(s):  
Fuhua Li ◽  
Tiemin Li ◽  
Yao Jiang ◽  
Fengchun Li
Keyword(s):  
Dynamic Model ◽  
Elastic Deformation ◽  
Control Method ◽  
Experimental Tests ◽  
High Accuracy ◽  
Compensation Method ◽  
Experimental Results ◽  
Ball Screw ◽  
Tracking Accuracy ◽  
Ball Screw Drives

Ball screw drives are widely used in machine tools to provide accurate linear motion. Elastic deformation is one of the major error sources for ball screw drives in achieving high accuracy motion, and changes greatly when velocity varies. The influence of velocity on the elastic deformation can be estimated and it can be compensated by means of dynamic modeling and servo control method. This paper presents a dynamic model considering torque transmission between the ball screw and the nut. And stiffness is identified by a method of combining theoretical calculation and experimental tests on a constructed test bench, which has two novel symmetrical loading mechanisms. In order to analyze the influence of moving velocity on the elastic deformation, simulation and experiments are conducted when two trajectories which have velocity jumps are input. And the simulated elastic deformations are compared with experimental results to evaluate the accuracy of the model. The results show that the simulated results fit the experimental results with high accuracy. The relationship between the elastic deformation of ball screw drives and the velocity is linear based on the experimental results. Then the simulation results are used to compensate the elastic deformation based on the feed-forward compensation method. The results show that the differences between the actual compensation values and actual elastic deformation are small and most of the elastic deformation of the ball screw drives can be compensated. Therefore, the proposed dynamic model and compensation method can be used to improve the tracking accuracy of ball screw drives.

scholarly journals Dynamic Modeling and Experimental Research on Position-dependent Behavior of Twin Ball Screw Feed System

2021 ◽  
Author(s):  
Meng Duan ◽  
Hong Lu ◽  
Xinbao Zhang ◽  
Zhangjie Li ◽  
Yongquan Zhang ◽  
...  
Keyword(s):  
Machine Tool ◽  
Dynamic Model ◽  
Machine Tools ◽  
Experimental Tests ◽  
Ball Screw ◽  
Fe Model ◽  
Feed System ◽  
Dependent Behavior ◽  
Machine Tool Structure ◽  
Important Means

Abstract To establish the dynamic model of machine tool structure is an important means to assess the performance of the machine tool structure during the cutting process. It’s necessary to study the dynamics of the machine tools in different configurations for the sake of analyzing the dynamic behavior of the machine tools in the entire workspace. In this paper, a robust approach is presented to build an efficient and reliable dynamic model to evaluate the position-dependent dynamics of the twin ball screw (TBS) feed system. First, the TBS feed system is divided into several components and a finite element (FE) model is built for each component. Second, the Craig-Bampton method is proposed to reduce the order of the substructures. Third, a multipoint constraints (MPCs) method was introduced to model the mechanical joints substructures of the TBS system, and the spring-damper element (SDE) is employed to connect the condensation nodes. Finally, a series experimental tests and full order FE analysis are conducted on the self-designed TBS worktable in the four positions to validate the effectiveness of the proposed dynamic model. The results show that the proposed approach evaluates accurately the position-dependent behavior of the TBS system.

Minimum Tracking Error Control of Flexible Ball Screw Drives Using a Discrete-Time Sliding Mode Controller

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Chinedum Okwudire ◽  
Yusuf Altintas
Keyword(s):  
Discrete Time ◽  
Error Control ◽  
Sliding Mode ◽  
Tracking Error ◽  
Open Loop ◽  
Ball Screw ◽  
Sliding Mode Controller ◽  
Tracking Accuracy ◽  
Ball Screw Drives ◽  
Tracking Error Control

This paper presents modeling, identification, and discrete-time sliding mode control of ball screw drives with structural flexibility. The mechanical system of the drive is modeled by a two degree-of-freedom system dominated by the coupled longitudinal and torsional dynamics of the drive assembly whose parameters are identified. A mode-compensating disturbance adaptive discrete-time sliding mode controller is then designed to actively suppress the vibrations of the drive. However, it is shown theoretically that, without using minimum tracking error filters, the tracking errors of the drive do not go to zero when sliding mode is reached. Therefore, a method for designing stable and robust minimum tracking error filters, irrespective of the identified open-loop behavior of the drive is proposed. The identification and control of flexible ball screw drives are experimentally tested, and the tracking accuracy of the drives is shown to improve considerably as a result of the designed minimum tracking error filters.

scholarly journals The transmissibility of a vibration isolation system with ball-screw inerter based on complex mass

2018 ◽  
Vol 37 (4) ◽  
pp. 1097-1108 ◽  
Author(s):  
Huabing Wen ◽  
Junhua Guo ◽  
Yang Li ◽  
Yue Liu ◽  
Kun Zhang
Keyword(s):  
Vibration Isolation ◽  
Damping Ratio ◽  
Experimental Tests ◽  
Experimental Results ◽  
Ball Screw ◽  
Type Ii ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Complex Mass ◽  
Isolation Systems

The wide application of the ball-screw inerter for vibration isolation has made it increasingly important to precisely determine the vibration transmissibility of the isolation system. In this reported work, the transmissibility of a vibration isolation system containing an inerter was predicted by using a complex mass M* in the calculations. The reported theoretical analysis showed that in the design of the type II inerter-spring-damper and inerter-rubber vibration isolation systems, the inertance-mass ratio must be less than twice the damping ratio to achieve improved vibration isolation performance when designing the system. To validate the findings, experimental tests were conducted on the type II inerter-spring-damper and inerter-rubber vibration isolation systems with ball-screw inerter. The experimental results showed that, based on M*, the transmissibility of these two systems was close to the experimental results, which illustrated the rationale for using M*. The results of this reported study will help facilitate the parameter design and performance analysis of a vibration isolation system with an inerter.

scholarly journals A weighted voltage model predictive control method for a virtual synchronous generator with enhanced parameter robustness

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Leilei Guo ◽  
Zhiye Xu ◽  
Nan Jin ◽  
Yanyan Li ◽  
Wei Wang
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Output Voltage ◽  
Control Method ◽  
Synchronous Generator ◽  
Experimental Tests ◽  
Tracking Accuracy ◽  
The Stability ◽  
Parameter Robustness ◽  
Virtual Synchronous Generator

AbstractTo address the problem of insufficient system inertia and improve the power quality of grid-connected inverters, and to enhance the stability of the power system, a method to control a virtual synchronous generator (VSG) output voltage based on model predictive control (MPC) is proposed. Parameters of the inductors, capacitors and other components of the VSG can vary as the temperature and current changes. Consequently the VSG output voltage and power control accuracy using the conventional MPC method may be reduced. In this paper, to improve the parameter robustness of the MPC method, a new weighted predictive capacitor voltage control method is proposed. Through detailed theoretical analysis, the principle of the proposed method to reduce the influence of parameter errors on voltage tracking accuracy is analyzed. Finally, the effectiveness and feasibility of the proposed method are verified by experimental tests using the Typhoon control hardware-in-the-loop experimental platform.

High-Accuracy Locomotion Control Method for Automatic Docking between Mobile Self-Reconfigurable Microrobots

2013 ◽  
Vol 347-350 ◽  
pp. 143-147 ◽  
Author(s):  
Da Wei Zhang ◽  
Ling Mao ◽  
Xiao Ning Tang ◽  
Zhen Bo Li ◽  
Jia Pin Chen
Keyword(s):  
Control Method ◽  
High Accuracy ◽  
Experimental Results ◽  
Control Methods ◽  
Locomotion Control ◽  
Automatic Docking

A mobile self-reconfigurable microrobot actuated by MEMS-based electromagnetic micromotors is presented. Normal stepping control methods for electromagnetic micromotor are introduced. To improve the locomotion accuracy of the microrobot and the efficiency of automatic docking between them more, a Changeable Virtual Winding Method (CVWM) for high-accuracy microstepping control is developed. Experimental results demonstrate the feasibility of the concept.

scholarly journals An improved dynamic model of preloaded ball screw drives considering torque transmission and its application to frequency analysis

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771058 ◽  
Author(s):  
Fuhua Li ◽  
Yao Jiang ◽  
Tiemin Li ◽  
Yunsong Du
Keyword(s):  
Resonant Frequency ◽  
Dynamic Model ◽  
Dynamic Models ◽  
Experimental Results ◽  
Ball Screw ◽  
Axial Stiffness ◽  
Axial Thrust ◽  
Screw Drive ◽  
Proposed Model ◽  
Ball Screw Drive

A dynamic model of the ball screw drive is proposed in this article. It is revealed that when axial thrust is transmitted between the ball screw and the nut, extra torque is generated synchronously which is not proposed in existing dynamic models. And a physical model for studying the relationship between the thrust and the torque is proposed. A lumped dynamic model is established, and a kinematic compatibility equation describing motion transmission between rotary displacement and axial displacement is established. Then a preload model of a double-nut for analyzing the force and the deformation is built. An approach to analyze the first resonant frequency of the proposed model is described. Meanwhile, a tested bench with a novel preload-adjustable double-nut and two novel loading mechanisms is constructed. The axial stiffness of the supporting bearings and the preloaded double-nut is tested based on a measurement system. Then vibration tests are carried out to measure the first resonant frequency of the ball screw drive. Finally, contrastive analysis between experimental results and simulated results of three models is conducted. The results show that the proposed model agrees much better with the experimental results than the discrete model and the hybrid model do.

Yaw Galloping of a TLWP Platform Under High Speed Currents by Analytical Methods and its Comparison With Experimental Results

2017 ◽  
Author(s):  
Francisco Lamas ◽  
Miguel A. M. Ramirez ◽  
Antonio Carlos Fernandes
Keyword(s):  
High Speed ◽  
Production Systems ◽  
Experimental Tests ◽  
Experimental Results ◽  
Analytical Methodology ◽  
New Approach ◽  
Laboratory Facilities ◽  
Polynomial Curve ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Analyses

Flow Induced Motions are always an important subject during both design and operational phases of an offshore platform life. These motions could significantly affect the performance of the platform, including its mooring and oil production systems. These kind of analyses are performed using basically two different approaches: experimental tests with reduced models and, more recently, with Computational Fluid Dynamics (CFD) dynamic analysis. The main objective of this work is to present a new approach, based on an analytical methodology using static CFD analyses to estimate the response on yaw motions of a Tension Leg Wellhead Platform on one of the several types of motions that can be classified as flow-induced motions, known as galloping. The first step is to review the equations that govern the yaw motions of an ocean platform when subjected to currents from different angles of attack. The yaw moment coefficients will be obtained using CFD steady-state analysis, on which the yaw moments will be calculated for several angles of attack, placed around the central angle where the analysis is being carried out. Having the force coefficients plotted against the angle values, we can adjust a polynomial curve around each analysis point in order to evaluate the amplitude of the yaw motion using a limit cycle approach. Other properties of the system which are flow-dependent, such as damping and added mass, will also be estimated using CFD. The last part of this work consists in comparing the analytical results with experimental results obtained at the LOC/COPPE-UFRJ laboratory facilities.

The analysis on the influence of mixed sliding-rolling motion mode to precision degradation of ball screw

2021 ◽  
pp. 095440622098201
Author(s):  
Qiang Cheng ◽  
Baobao Qi ◽  
Hongyan Chu ◽  
Ziling Zhang ◽  
Zhifeng Liu ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Experimental Tests ◽  
Theoretical Models ◽  
Operating Conditions ◽  
Ball Screw ◽  
Rolling Motion ◽  
Degradation Model ◽  
Sliding Motion ◽  
Factors Analysis ◽  
Motion Mode

The combination of sliding/rolling motion can influence the degree of precision degradation of ball screw. Precision degradation modeling and factors analysis can reveal the evolution law of ball screw precision. This paper presents a precision degradation model for factors analysis influencing precision due to mixed sliding-rolling motion. The precision loss model was verified through the comparison of theoretical models and experimental tests. The precision degradation due to rolling motion between the ball and raceway accounted for 29.09% of the screw precision loss due to sliding motion. Additionally, the total precision degradation due to rolling motion accounted for 21.03% of the total sliding precision loss of the screw and nut, and 17.38% of the overall ball screw precision loss under mixed sliding-rolling motion. In addition, the effects of operating conditions and structural parameters on precision loss were analyzed. The sensitivity coefficients of factors influencing were used to quantitatively describe impact degree on precision degradation.

Constraint-force driven control design for rail vehicle virtual coupling

2021 ◽  
pp. 107754632110079
Author(s):  
Bin Wang ◽  
Dengke Yang ◽  
Xinrong Zhang ◽  
Xingheng Jia
Keyword(s):  
Dynamic Model ◽  
Traffic Management ◽  
Control Method ◽  
Constraint Force ◽  
Explicit Equation ◽  
Coupling Problem ◽  
Railway Traffic ◽  
Rail Vehicle ◽  
Virtual Coupling ◽  
Traffic Management System

This study investigates the constraint-force driven control problem of virtual coupling. To solve the constraint force, the explicit equation of vehicle motion with equality constraints is established using the Udwadia–Kalaba approach. First of all, this study introduces a brief overview of virtual coupling concepts in the European Railway Traffic Management System and some scenes of virtual coupling. The control method is proposed to enable the mechanical system to follow the designed constraint. Moreover, the dynamic model for virtual coupling problem is established. Second, combined with the dynamic model, the equation constraint is designed to make the rail vehicle movenment reach the control objective. By solving the equation based on the Udwadia–Kalaba approach, the control inputs that can render the vehicle to move along the desired trajectory. Third, numerical simulation results demonstrate the effectiveness of the proposed method in virtual coupling problem.

scholarly journals The Boundary Proportion Differential Control Method of Micro-Deformable Manipulator with Compensator Based on Partial Differential Equation Dynamic Model

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 799
Author(s):  
Xiangli Pei ◽  
Ying Tian ◽  
Minglu Zhang ◽  
Ruizhuo Shi
Keyword(s):  
Differential Equation ◽  
Partial Differential Equation ◽  
Dynamic Model ◽  
Control Method ◽  
System Modeling ◽  
Working Environment ◽  
Partial Differential ◽  
External Interference ◽  
Differential Control ◽  
Differential Control Method

It is challenging to accurately judge the actual end position of the manipulator—regarded as a rigid body—due to the influence of micro-deformation. Its precise and efficient control is a crucial problem. To solve the problem, the Hamilton principle was used to establish the partial differential equation (PDE) dynamic model of the manipulator system based on the infinite dimension of the working environment interference and the manipulator space. Hence, it resolves the common overflow instability problem in the micro-deformable manipulator system modeling. Furthermore, an infinite-dimensional radial basis function neural network compensator suitable for the dynamic model was proposed to compensate for boundary and uncertain external interference. Based on this compensation method, a distributed boundary proportional differential control method was designed to improve control accuracy and speed. The effectiveness of the proposed model and method was verified by theoretical analysis, numerical simulation, and experimental verification. The results show that the proposed method can effectively improve the response speed while ensuring accuracy.

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